We are at a point in history where we can either choose to dedicate ourselves to sustainability or oblivion. Since perfect performance depends on building something properly and then maintaining it, efficiency is fragile. As a result, we have to find cost-effective and practical solutions to the everyday problems of construction and operations to be meaningfully sustainable. We have to focus on things that don't get a TED talk or applause at a podium. Things like maintenance, commissioning, and vendor testing have become the front-line battlegrounds for the future.In 2019, I worked with my customers and multiple Air Handler manufacturers to install custom AHU controls at the factory, and tested the controls at the manufacturer's facilities. This approach allowed us to implement custom high-performance sequences while allowing on-site personnel to own the programming for future modifications (which allowed us to make rapid changes to OA intake for COVID). The costs were more than offset by the reduced construction timeline, as many of the AHUs were installed and commissioned over a single weekend.Broken things can eliminate otherwise brilliant optimizations. To prevent this, my team has worked to implement a system of VAV diagnostics that provides operators with actionable data about manual overrides and damper, sensor, and valve failures. This system ties into the request logic to suppress pressure, temperature, and heating requests from malfunctioning boxes.